AAA : Amateur Athletics Association formed in 1880.

  ABA : Abscisic Acid.

  ACAS : Agricultural Chemicals Approval Scheme.

  ACC : Acrylic Colour Coat.

  ACHIEVE [1] : Assess, Creative, Hone, Initiate, Evaluate, Valid, Encourage. A 7-stage coaching model.

  ACOP : Approved Code of Practice.

  ADDIE : Analysis, Design, Development, Implementation, and Evaluation.

  ADP : Adenosine diphosphate.

  AE : Acid Equivalent.

  AEA : Agricultural Engineers Association.

  AELTC : All England Lawn Tennis and Croquet Club, based at Wimbledon.

  AFP : Air-Filled Porosity.

  AGCSA : Australian Golf Course Superintendents Association.

  AGP [1] : Artificial Grass Pitch.

  AGP [2] : Artificial Grass Paint.

  AGQ : Applied General Qualification.

  AHDB : Agriculture and Horticulture Development Board.

  AI [1] : Active Ingredient.

  AI [2] : Activity Index.

  AI [3] : Artificial Intelligence.